Improved Securitron Secborg Sprites

Main sprites by headshotter, not me. The only edits I did were for on/off and movement states.

Pic:
![c0cdca5a-6cfe-11e4-8cd1-64c383fd6eab](https://cloud.githubusercontent.com/assets/7810719/5058854/28025de8-6cc9-11e4-865e-f67c3fc226b7.gif)